Device for Supporting a Wire, Felt or Paper Web in a Paper Production Plant

ABSTRACT

A device for supporting a wire or felt in a paper production plant or the paper web produced in the plant. The supporting device includes at least one rotatably mounted supporting roll or the like. The at least one supporting roll or the like is mounted in a bearing shell and, on the side facing away from the wire, the felt or the paper web, can have applied to it a medium capable of flowing, specifically a liquid or a gas, by which means it is kept at a distance from the bearing surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority, under 35 U.S.C. § 119, of Austrianapplications A 1924/2006, filed Nov. 21, 2006 and A 495/2007, filed Mar.29, 2007; the prior applications are herewith incorporated by referencein their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a device for supporting a wire or feltin a paper production plant or the paper web produced in the plant. Thesupporting device has a rotatably mounted supporting roll or the like.

In paper production plants, there are at least one wire and at least onefelt adjoining the latter in the direction of movement, the two beingmoved in the plants at high speeds. At the start of its movement path, apaper stock is sprayed onto the wire. Along the movement path of thewire, the liquid contained in the paper stock is led away through thewire, in particular sucked away. The web of paper produced as a resultis then transferred to the felt, on which it is dried. The paper web isthen detached from the felt and processed further, in particular driedfurther and rolled.

Wires, felts and paper webs in such paper production plants have widthsof up to 12 m, which are moved along the plant at speeds of about 30m/sec.

The wires and felts located in the plants, and also the paper webs, canbe guided during their movement in the plant on supporting rolls, whichextend over the entire width of the plant and which are mounted at theirtwo ends. Because of the great length of the supporting rolls andbecause of the fact that the wires, felts or paper webs bear on thesesupporting rolls with high pressure, the latter have to be formed withlarge diameters, which necessitates high constructional expenditure. If,in addition, suction devices are assigned to the wire or felt,supporting rolls of this type cannot be used, however, since theinterspace located between them, by which the suction channel isdelimited, is so small in relation to that area which is subjected tothe suction action that, as a result, no suction action meeting therequirements is achieved.

For this reason, it is not possible to support by means of rolls of thistype such regions of the wire or of the felt in which suction devicesare arranged.

In order to avoid the disadvantages adhering to the known supportingrolls, in order to support the wires or the felts, it is moreover knownto provide supporting strips extending over the width of these wires orfelts, which are provided with a wearing layer formed by plates of aceramic material on their side assigned to the wires or felts.Supporting strips of this type are advantageous inasmuch as, with smalldimensions, they exhibit high strength or rigidity, since they can bearranged beside one another at any desired small distances, sincesuction channels meeting the requirements can be provided between themand since, additionally, they also serve as wiping strips for the liquidreaching the underside of the wire.

Wiping strips of this type are disadvantageous, however, since they arevery expensive to produce because of the formation using plates of aceramic material and since very high frictional forces occur betweenthem and the wires or felts resting on them. As a result of these highfrictional forces, firstly a high drive output is required for themovement of the wires or the felts. Secondly, because of thesefrictional forces, very high thermal loadings and thermal stressescaused by these occur in the plates of a ceramic material, as a resultof which the latter can fracture, whereupon they have to be replaced. Inaddition, both the plates of a ceramic material and the wires and thefelts moving over these supporting strips are subjected to very highwear.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a supportingdevice for a wire, a felt, or a web in a paper-production facility whichovercomes the above-mentioned disadvantages of the heretofore-knowndevices and methods of this general type and which provides for a devicethat supports at least one wire, at least one felt, or the web of paperand which avoids the disadvantages adhering to the prior art supportingroll.

With the foregoing and other objects in view there is provided, inaccordance with the invention, a supporting device in a paper productionplant, for supporting a wire, a felt, or a paper web produced in thepaper production plant. The supporting device comprises:

a bearing shell having a bearing surface;

at least one supporting roll rotatably mounted in the bearing shell;

the bearing shell being configured for subjecting the supporting roll,on a side thereof facing away from the wire, the felt, or the paper web,to a fluidic medium (i.e., a flowable medium such as water or compressedair) for spacing said supporting roll a distance from the bearingsurface.

In other words, the objects of the invention are achieved in that the atleast one supporting roll or the like is mounted in a bearing shell and,on the side facing away from the wire, felt or the paper web, can haveapplied to it a medium capable of flowing, specifically a liquid or agas, by which means it is kept at a distance from the bearing surface.

Preferably, at least one channel for the supply of the medium capable offlowing opens into the bearing shell. In this case, the at least onechannel for the supply of the medium capable of flowing can beconstructed with a nozzle-like narrowing and the at least one openingprovided in the bearing shell for the medium capable of flowing can beconstructed with a widened region, in particular with a dome or with aslot. In addition, a valve, in particular a non-return or check valve,can be located in the at least one supply channel for the medium.

According to a preferred embodiment, the at least one supporting rollcan also have a medium capable of flowing applied to its end faces.Furthermore, the at least one supporting roll or the like is at leastpartly embraced by a cover over which the at least one supporting rollor the like projects in the position of the latter in which medium isapplied to it. In this case, as seen in the axial direction, in eachcase a cover can also be provided on both sides of the at least onesupporting roll or the like.

According to a further preferred embodiment, a plurality of supportingrolls, supporting rollers or supporting balls is provided, which aremounted in at least one bearing shell and which are located beside oneanother and possibly also one after another in the direction of movementof the wire, of the felt or of the web of paper. In this case, at leastsome of the supporting rolls, supporting rollers, supporting balls orthe like can be located on a common carrier for the bearing shells.

According to a further preferred embodiment, supporting rolls or thelike can also be provided on both sides of the wire, of the felt or ofthe web of paper, suction channels, which are connected to a suctiondevice, being located between two supporting rolls or the like locatedbeside each other.

In order to be able to perform very effective cleaning of a felt, therolls or the like which are located on both sides of the felt and whichextend transversely with respect to the felt are furthermore preferablyoffset in relation to one another in the longitudinal direction of thefelt, a supporting roll or the like arranged on one side projecting intothe space found between two supporting rolls or the like arranged on theother side, which means that the felt is moved in a wavy course betweenthe mutually opposite supporting rolls or the like. In this case, aspraying device is assigned to the felt.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin device for supporting a wire, felt or paper web in a paper productionplant, it is nevertheless not intended to be limited to the detailsshown, since various modifications and structural changes may be madetherein without departing from the spirit of the invention and withinthe scope and range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a sectional view of a first embodiment of a device accordingto the invention in a first implementation, specifically for supportinga wire;

FIG. 2 is a sectional view of a second embodiment of a device accordingto the invention;

FIG. 3 is a sectional view of a second implementation of a deviceaccording to the invention;

FIG. 4 is a side view of a third implementation of a device according tothe invention;

FIGS. 4A to 4D are side views showing four different further embodimentsof a device according to the invention; and

FIG. 5 is a front view of a fourth implementation of a device accordingto the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the figures of the drawing in detail and first,particularly, to FIG. 1 thereof, there is shown a wire 1 in a paperproduction plant, which is supported by a supporting roll 2. Thesupporting roll 2 is mounted in a bearing shell 3. The bearing shell 3is constructed with an approximately semi-cylindrical bearing surfaceand with flat end faces at the ends. In addition, the bearing shell 3 isconstructed with three channels or conduits 4 for the supply of afluidic medium, i.e., a flowable medium, such as water or compressedair. The channels open in the bearing surface. In addition, the endfaces are also constructed with openings, to which a medium capable offlowing is led. In this case, at their ends facing the openings 5, thesupply channels 4 are each constructed with a taper 6, by means of whichthe entry of contaminants into the channels 4 is prevented. In order toensure a uniform feed flow of the medium to the supporting roll 2, theopenings 5 of the channels 4 are also in each case constructed with awidening. By this means, the most uniform loading of the supporting roll2 over its entire region located in the bearing shell 3 is achieved. Inaddition, check valves or non-return valves are in each case provided inthe supply channels.

As a result of the application of a medium to the supporting roll 2, thelatter is raised in the bearing shell 3 in the direction of the arrow A,by which means it is held at a distance with respect to the bearingsurface and also with respect to the end faces, so that it can berotated virtually without friction in the bearing shell 3.

The supporting roll 2 can also be used in the same way as a rest for afelt or for the web of paper produced in the plant.

Because of the fact that the supporting roll 2 is mounted in the bearingshell 3 over its entire length, it can be constructed with a relativelysmall diameter irrespective of its length without its serviceabilitybeing reduced as a result. In this regard, it is pointed out that thesupporting roll 2 can extend over the entire width of the wire 1, of thefelt or of the web of paper, and that a plurality of coaxial supportingrolls or other supporting elements can be provided over the width of thewire, felt or web.

FIG. 2 illustrates a second embodiment of a device according to theinvention, in which the supporting roll 2 is constructed with covers 7arranged at the sides, which are bent over toward the supporting roll 2in the upper region, which means that lifting of the supporting roll 2beyond a predefined extent is limited. The covers 7 are in this casefixed to the bearing shell 3 by means of screws 8. Furthermore, thebearing shell 3 is fixed to a plate-like carrier 10, which is pierced bythe three supply channels 4 and in whose lower region there is a recess11, from which the three supply channels 4 originate.

By using FIG. 3, the use of such a supporting roll 2 as a breaker rollin a paper production plant will be explained. Breaker rolls are used toalign the web of paper 13 in a cross-cutter. In this case, the web ofpaper 13 is led over a first deflection roll 14, then over thesupporting roll 2 and also over a second deflection roll 15. In order tobe able to adjust the extent of the bending of the web of paper 13, thecarrier 10 can be displaced vertically.

In FIG. 4, three supporting rolls 2 arranged beside one another in thedirection of movement of the wire 1 or the felt are illustrated, betweenwhich there are suction channels 16. In this case, the carriers 10 arefixed by means of screws 10 a to a support 17, which is constructed withsuction channels 16 a connected to a suction device. By means of thisarrangement, a suction force can be applied to the wire 1 or the feltbetween the supporting rolls 2.

Three further embodiments will be explained with reference to FIGS. 4Ato 4D:

In the embodiment illustrated in FIG. 4A, the supporting roll 2 extendsover the entire width of the paper production plant.

In the embodiment illustrated in FIG. 4B, instead of a single supportingroll, four coaxial supporting rolls 21 arranged beside one another areprovided, on which the wire or the felt rests.

In the embodiment illustrated in FIG. 4C, the individual supportingrolls 21 a are crowned.

In the fourth embodiment, illustrated in FIG. 4D, instead of supportingrolls arranged beside one another, a group of supporting balls 21 barranged beside one another and possibly after one another in thedirection of movement are provided, which extend over the width of thewire, felt or web carried by these.

The supporting rolls 21, the supporting rolls 21 a and the supportingballs 21 b can be located beside one another and additionally also oneafter another in the direction of movement of the wire 1 or felt.

All the supporting elements are assigned side covers 7. The arrangementof individual supporting rolls or the like located beside one another isadvantageous since, as a result, a suction action can also be exerted onthe wire or the felt between these individual supporting elements.

A supporting device according to the invention is thus advantageoussince, for the movement of the at least one wire or the at least onefelt, it requires only low drive outputs, since the wear of thesupporting elements, on one hand, and of the wire or the felt is low andsince, between the supporting elements, there is sufficient space forsuction channels in order to be able to apply to the wire or to the feltappropriate suction forces meeting the requirements.

FIG. 5A illustrates a further development of the device according toFIG. 4, in which, on both sides of a felt 1 a, a plurality of suchsuction rolls 2 is provided, between which there are suction channels 16connected to a suction device. In this case, the supporting rolls 2located on one side of the felt 1 a in each case are offset with respectto the supporting rolls 2 located on the other side of the felt 1 a inthe longitudinal direction of the felt 1 a, and they project into thespaces between the supporting rolls 2 provided on the other side of thefelt 1 a, which means that the felt 1 a is moved in a wavy course. Thesupporting rolls 2 located on the two sides of the felt 1 a canpreferably be displaced with respect to each other, which means that thewavy course of the felt 1 a can be adjusted.

For the cleaning of a felt 1 a, a spray pipe 9 oriented transverselywith respect to the movement path of the felt 1 a is provided, by meansof which a cleaning liquid 9 a can be applied to the felt 1 a. By meansof such an arrangement, very effective cleaning of the felt 1 a isachieved.

1. A supporting device in a paper production plant, for supporting awire, a felt, or a paper web produced in the paper production plant, thesupporting device comprising: a bearing shell having a bearing surface;at least one supporting roll rotatably mounted in said bearing shell;said bearing shell being configured for subjecting said supporting roll,on a side thereof facing away from the wire, the felt, or the paper web,to a fluidic medium for spacing said supporting roll a distance fromsaid bearing surface.
 2. The device according to claim 1, wherein saidfluidic medium is a medium capable of flowing selected from the groupconsisting of a liquid and a gas.
 3. The device according to claim 1,wherein at least one channel for supplying the fluidic medium opens intosaid bearing shell.
 4. The device according to claim 3, wherein said atleast one channel is constructed with a nozzle-type narrowing.
 5. Thedevice according to claim 1, wherein said bearing shell is formed withat least one opening through which the fluidic medium flows, and saidopening is formed with a widened region.
 6. The device according toclaim 5, wherein said widened region in the bearing shell is a dome or aslot.
 7. The device according to claim 1, which comprises a valvedisposed in at least one supply channel for the fluidic medium.
 8. Thedevice according to claim 7, wherein said valve is a check valve.
 9. Thedevice according to claim 1, wherein said at least one supporting rollis disposed to have a fluidic medium applied to end faces thereof. 10.The device according to claim 1, which comprises a cover at least partlyembracing the supporting roll, and wherein said supporting roll projectsout of said cover in a position in which the fluidic medium is appliedto said supporting roll.
 11. The device according to claim 10, wherein,as seen in an axial direction, in each case a cover is provided on thetwo sides of said at least one supporting roll.
 12. The device accordingto claim 1, wherein said at least one supporting roll is one of aplurality of supporting rolls, supporting rollers, or supporting balls,mounted in at least one said bearing shell and disposed beside oneanother.
 13. The device according to claim 12, wherein said plurality ofsupporting rolls, supporting rollers, or supporting balls are disposedone after another in a direction of movement of the wire, the felt, orthe web of paper.
 14. The device according to claim 12, wherein at leastsome of said supporting rolls, supporting rollers, or supporting ballsare supported on a common carrier for said bearing shells.
 15. Thedevice according to claim 12, wherein at least one supporting roll isprovided on each side of the wire, the felt, or the web of paper. 16.The device according to claim 12, which comprises a suction device andone or more suction channels issuing at a location between two saidsupporting rolls.
 17. The device according to claim 15, wherein saidsupporting rolls on opposite sides of the felt and extendingtransversely with respect to the felt are offset in relation to oneanother in a longitudinal direction of the felt, a respective saidsupporting roll arranged on one side projecting into a space between tworespective supporting rolls arranged on the opposite side, to define awavy course of the felt between the mutually opposite supporting rolls.18. The device according to claim 17, which comprises a spraying devicedisposed to spray the felt.